This application is re-submitted as Phase I instead of Fast Track per recommendation of reviewers. The Phase I is to perform preliminary tests of new designs of the polytetrafluoroethylene graft (PTFEG) used as vascular access for hemodialysis, in a setting simulating hemodialysis (inside a prototype of the new graft, using flow rates of the venous needle and of the graft similar to the one found during dialysis). The goal is to demonstrate whether the new designs decrease the velocity and turbulence of the post-venous needle flow at the venous anastomosis when compared with the existing graft. The studies will include development of Plexiglas prototypes of the grafts and of a system to simulate hemodialysis, fluid mechanics experiments to measure velocity and turbulence of the post-venous needle flow for flow patterns and qualitative determination of velocity, turbulence and recirculation by flow visualization. If the new grafts cause less velocity/turbulence a Phase II study will include additional fluid dynamic studies and animal and human studies to demonstrate effectiveness and safety. The new PTFEGs are expected to decrease access morbidity, prolong access life, decrease cost of care and improve dialysis efficiency. PROPOSED COMMERCIAL APPLICATION: The new graft should replace the currently used design of the graft. There are about 300,000 ESRD patients in the U.S.A. Approximately 185,000 of existing and new patients receive new grafts every year. Baxter Healthcare, inc. would commercialize the product if proven to be safe and effective.